I’ve tried both, working alone on games, and also partnering up with others. I’m not talking about working on Breakout clones, but rather end-product indie games that can potentially be sellworthy.
Working alone is least complicated, but can be boring, dull down your interest, and simply be difficult to develop since you don’t have anyone to throw ideas at, get feedback from, and share the complexity burden with. You have to do everything A-Z, sounds, graphics, code, AI, networking, etc. etc. Each task can quickly evolve into a few weeks worth of research. A single developer cannot mentally work on all aspects.
But I’ve also tried partnering with others, and that’s been a horrible experience. Out of all the projects I’ve been involved, and all the partners I’ve worked with, only 1 has not disappeared absolutely within 1 week, but that person was still only 1/3 as active as I was, although he did do work for 3 months. Most of these people seem to be very green as well. But really, do people join projects as a laugh? The worst part with a partner that is absent is that you think you have someone to work with, throw ideas at, but just isn’t there.
I simply do not understand why it’s so difficult to find a proper partner to develop games with. There seem to be a lot of individual game developers out there in the same situation, but somehow it seems near impossible for people to cooperate.
All these resources working alone and produce nil.
Ok, what is this post all about? Just ranting. It’s healthy to do sometimes.

